Invalid request

request.invalid · HTTP 400, 405, 408, 413, 415 or another 4xx

What it means

The request could not be accepted as sent: a parameter or body field failed validation, the body is not valid JSON, or the HTTP method or content type is not one the route accepts (answered with 405 or 415 rather than 400). A message sent to POST /v1/inboxes/{id}/messages whose body arrived too slowly, under 64 KB a second after its first five seconds, is answered with 408. When fields failed validation, the problem's errors field names each one with what is wrong.

What to do

Correct the fields named in errors (or the request as the detail describes) and send it again. After a 408, send the message again once it can be uploaded faster; nothing was stored. The API reference lists each route's parameters and their limits.

Every error the API returns is a JSON problem (RFC 9457) whose code names it and whose type links to its page here. See the docs for how the API works.